Electric water heater



Oct. 23,A 1951 w. B. HARRIS 2,572,337 l ELECTRIC WATER HEATER Filewsept.13, 194e 9 33 34 BY ATTORNEY Patented ct. 23, 1951 UNITED STATES PATENTGFFICE Claims.

This invention relates to an instantaneous water heater, andparticularly to one in which the heating is effected by the passage ofcurrent through the water.

Heaters of this character usually employ spaced carbon electrodesbetween which the water circulates. 'I'hese electrodes may be ilatplates or circular.

In many installations, it is desirable readily to adjust the temperatureof the water at the outlet.

It is one of the objects of this invention to make it possible, in asimple manner, to adjust the spacing of the electrodes for effectingthis result.

It is another object of this invention to provide an improved form ofheater of this general character. Y

This invention possesses many other advantages, and has other objectswhich may be made more clearly apparent from a consideration of oneembodiment of the invention. For this purpose there is shown a form inthe drawings accompanying and forming part of the present specification.The form will now be described in detail illustrating the generalprinciples of the invention; but it is to be understood that thisdetailed description is not to be taken in a limiting sense, since thescope of this invention is best dened by the appended claims.

Referring to the drawings:

Figure l is a vertical section of a heater incorporating the invention;and

Fig. 2 is a partial sectional view, taken along the plane indicated byline 2 2 of Fig. 1.

The heater includes a stationary electrode I made of carbon or graphite.This electrode is shown as having a cylindrical exterior surface and aconical active electrode surface 2. A cooperating electrode 3, which mayalso be made of carbon or graphite, is shown as having an active,conical electrode surface 4. The axis of the two conical surfaces arecoincident, and the slopes of the cones are identical. This common axiscorresponds to the axis of the housing 5 in which the electrodes areaccommodated.

The housing 5 is also shown as cylindrical, and is preferably made intwo parts to facilitate assembly of the heater. The lower part 6 of thehousing may be made from insulation material, such as Bakelite, or thelike. The electrode I rests upon the bottom surface 'I thereof. A numberof screws, such as 8, pass through the bottom and engage threadedapertures in the bottom of the electrode I to hold it firmly in place.One

of these screws can serve as a terminal for a source of supply,connection to which is made by the aid of a lead 9.

The upper part IU of the housing 5 is also made of insulation materialsimilar to that utilized for the lower part 6. It has a depending flangeI I contacting the upper edge of the part 6.

The parts are held rmly together by the aid of a jacket structureformed, in this instance, of metal. The inner wall I2 of this jacketstructure may be formed as a tubular element with an upper flange I3.This tubular element closely encompasses the exterior cylindricalsurfaces of the parts 6 and I0. The outer wall I4 of the jacketstructure defines with inner wall I2, an annular space I5. The two wallsI2 and I4 may be joined together as by welding, as indicated at I6.

The outer wall I4 has an inwardly turned flange Il engaging the lowersurface of the housing member 6.

In order to hold the parts firmly together, a clamp ring I8 is utilized.Through the clamp ring I8 and the flange I3 a number of bolts I9 areprovided. In order to render the housing fluid-tight, the upper andlower edges of the housing` 5 are bevelled, as indicated at 20, for theaccommodation of the circular compressible gaskets 2I. The upper gasket2| is accommodated in the space formed between the clamp ring I8, thehousing member IU, and the inner wall I2.

The lower gasket 2| is similarly accommodated in the space formedbetween the flange Il, the inner wall I2, and the housing member 6.

The inlet to the space 22, formed between the electrodes I and 3, isprovided by the aid of a number of slots or apertures 23 disposed in thetop edge of the housing member 6. These openings are in communicationwith the annular space I5, as by appropriately formed apertures 24 inthe inner wall I2. Connected to the lower portion of the jacket is aninlet pipe 25. This inlet pipe 25 is shown, as having an exteriorlythreaded portion, to accommodate an appropriate coupling leading to asource of cold water supply. The amount of flow may be regulated by aneedle valve 2B threaded transversely through the pipe 25. This needlevalve interposes an adjustable barrier to the flow of water through theinlet passage 21. The pipe 25 may be appropriately welded to theexterior wall I 4.

The outlet pipe 28 is shown as extending through the outer wall I4 ofthe jacket, and attached, as by welding, to both the inner and outerwalls of the jacket. It may be provided with interior and externalthreads for an appropriate coupling for the discharge of the heatedwater through the discharge opening 29. This discharge openingcommunicates with the aperture 3I arranged radially in the bottom ofhousing member 6. This aperture 3| leads to the lower portion of thespace 22 between electrodes I and 3.

The path ofV the water, therefore, is a some- 1' what tortue-us one. Theincoming water passes through the inlet opening 21, thence upwardlythrough the space I5, through the openings 24 and 23, thence downwardlythrough the space 22, and out to the discharge opening 29 by Way of theradial aperture 3I.

The electrode 3 is arranged to be adjusted along its axis to vary thespacing between the active surfaces 2 and i of the electrode. In thisway, the amount of electrical energy converted i into heat may becontrolled and thereby the outlet temperature of the water may bedetermined.

In order to adjust the electrode 3, itis mounted upon Ia metal stem 32.This stem 32 has a lower cylindrical portion 33 rotatably mounted in aboss 313 provided in the bottom of the housing member 6. The stem 32 isthreaded, and the electrode 3 is nrmly mounted on the threads andprevented from relative rotation with respect to the stem 32. The upperthreaded portion of the stem 32 is in engagement with the internalthreads 3ft of a conducting member 35 which may be made of brass, or thelike. This conducting member: 35 is firmly attached to the cover Ill,.as by the aid of the annular groove 35 in which the cover or top Ill ismolded.

In order to adjust the height of electrode 3, the stem 32 may be rotatedso that the upper part of the stem is threadedly moved into or out ofthe member 35. Since the stem 32 is made of metal, the connection to theelectrode 3 may be readily effected by the aid of a terminal 31fastened, as by a screw 33, to the upper sloping wall of member 35.

The stem 32 is provided with an extension 39 which passes out-of thehousing and which is provided with a non-circular end 4D, facilitatingthe use of a wrench for angularly moving the stem 32. In order toprovide against leakage past the extension 39, the member 35 has ahollow extension 4I for accommodating a cylindrical, compressiblepacking member 42. This packing member closely ysurrounds extension 39.It rests upon a washer 43 above the threaded portion 34. The packing iscompressed by the aid of the packing gland nut d4 threaded on theexterior of the portion 4I. A washer 45 is .inserted between the nut i4and the top of the packing 132.

Upon rotation of the stem 32, the width of the space 22 can be readilyadjusted. Since the Y slopes of the conical surfaces 2 and 4 areidentical, the space 22 between these surfaces remains uniform, allaround the electrodes, for all adjustments of electrode '3. Furthermore,`it is to be noted that, upon adjustment, the electrode 3 rotates withthe stem 32. Thus, there is relative angular motion between the activesurfaces 2 and d upon adjustment of the electrode 3. In this way, anytendency for the surfaces to develop substantial irregularities overlong periods of operatic-n is reduced, since new portions of the surfacei are presented to the cooperating lsurface 2.

To facilitate assembly of the heater, the inner wall I2 of the jacketmay be tapered so that its upper end has a slightly larger diameter thanits lower end, the outer and inner surfaces of the housing 5 beingcorrespondingly tapered, as is also the outside surface of thestationary electrode I. For example, the upper end of the inner wall I2may have an inside diameter of 3.750,'the outer jacket wall having auniform diameter of four inches. In this way, insertion of the electrodeI into the lower part 3 of the housing is facilitated, as well as theinsertion of lower part 6 and the upper part I0 of the housing into thejacket.

The inventor claims:

l. In a liquid heater: a housing made from insulation material; anelectrode fastened in the housing and having an active surface ofrevolution generated by a line oblique to the axis of revolution; acooperating electrode having an active surface of revolution uniformlyspaced from said iirst surface; means for adjusting said cooperatingelectrode along the axis of revolution; and means forming an annularspace on the exterior of the housing and in communication with theinterior of the housing.

2. In a liquid heater: a housing made from insulation material; anelectrode fastened in the housing and having an active surface ofrevolution generated by a line oblique to the axis of revolution; acooperating electrode having an active surface of revolution uniformlyspaced from said first surface; means f or adjusting said cof`Aoperating electrode along the axis of revolution; there being one ormore openings in the housing' above the electrodes; means forming anannular space around the housing and communicating with the electrodes;means forming an inlet to' the annular space; and means forming an outlefrom the space between the electrodes.

3. In a liquid heater: a housing made from insulation material; anelectrode in the bottom of the housing and having an internal conicalactive surface, the axis of the surface being substantially'vertical; acooperating electrode having an external conical active surface, coaxialwith the internal surface and having the same slope; a stem carryingvthe cooperating electrode and having threads at its upper portion, saidstem having an extension projecting from the top of the housing; meanscarried by the top of the housing in which the threads engage, forcausing the stern to move axially when rotated; and means forming anannular space around the housing and in communication with the housingadj acent the top of the housing.

4. In a liquid heater: a hollow housing of insulation material having aseparable top portion; an electrode having an interior conical activesurface having an axis extending substantially vertically and carried atthe bottom of the housing; a' cooperating electrode coaxial with saidrst 'electrode and having an exterior active conical sur-face of thesame slope as the interior surface; a stem carrying said secondelectrode and having an extension projecting out of the top of thehousing; a metallic member carried by the top of the housing and inthreaded engagement with the stem; means forming a jacket around thehousing, said jacket having an inlet communicating with the interior ofthe housing adjacent the top thereof, said jacket serving y-as a casingfor the housing; and clamping "means for holding the housing in thecasing.

5. In a liquid heater: a housing made .from

insulation material; an electrode fastened in the housing and having anactive surface of revolution generated by a line oblique to the axis ofrevolution; a cooperating electrode having an active surface ofrevolution uniformly spaced from said first surface; means for adjustingsaid cooperating electrode along the axis of revolution; means, exteriorof the housing and cooperating with the housing to form an annular spacearound said electrode which is fastened in the housing, there being oneor more openings above the electrodes establishing communication betweensaid annular space and the space between the electrodes; means formingan inlet to the annular space; and means forming an outlet from thespace between the electrodes.

WILLIAM B. HARRIS.

REFERENCES CITED The following references are of record in th file ofthis patent:

UNITED STATES PATENTS Number Name Date 727,361 Hill May 5, 1903 758,095Neely Apr. 26, 1904 891,254 Hill June 23, 1908 10 1,356,846 Young Oct.26, 1920 2,355,687 Van Hise Aug. 15, 1944 2,403,334 Blanchard July 2,1946 4

